JUST WATCHED

Time-lapse: The Shard built in 1 minute

MUST WATCH

JUST WATCHED

London's newest landmark: The Shard

MUST WATCH

London's newest landmark: The Shard03:28

"They expect the grueling project to take most of the day," it read. "The lead climbers are 'free climbing' (scaling the building without assistance) but are fixing safety ropes as they progress. They are carrying the huge work of art in backpacks and will install it this afternoon if they reach the summit. "

The six started their climb of the 1,016-foot-tall skyscraper at dawn and were live streaming the climb.

They opted to climb The Shard because it towers over the oil giant's global headquarters on the South Bank of the Thames, according to the statement .

"Shell is leading the oil companies' drive into the Arctic, investing billions in its Alaskan and Russian drilling programs," it said. "A worldwide movement of millions has sprung up to stop them, but Shell is refusing to abandon its plans."

The climbers are from the United Kingdom, Canada, Sweden, Poland, Holland and Belgium.

The Shard released a statement saying it is working with authorities to ensure the climbers' safety, reading, "Our primary focus is on the safety of the protesters, and of the workers and visitors to our building, which remains open today."

Greenpeace's environmental campaign aims to turn the area around the North Pole into a global sanctuary unavailable to industrialization.

Shell defended its Arctic drilling.

"Oil and gas production from the Arctic is not new," it said in a statement. "The Arctic region currently produces about 10% of the world's oil and 25% of its gas. If responsibly developed, Arctic energy resources can help offset supply constraints and maintain energy security for consumers throughout the world."

Regarding the protest, the oil giant said it respects the freedom of expression.

"We only ask that they do so with their safety and the safety of others, including Shell personnel and customers in mind," Shell said.